<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body html {
            width: 100%;
            height: 100%;
        }

        .flex {
            display: flex;
            width: 100%;
            height: 100%;
            /* background-color: red; */
        }

        .flex div {
            flex: 1;
            /* background-color: cyan; */
            /* width: 300px;
            height: 300px; */
        }
    </style>
    <script type="module">
        import('https://cdn.jsdelivr.net/npm/dayjs@1.11.11/+esm').then(res => {
            console.log(res);
        })
        const arr = [1, 2, 3];
        const brr = [1, 2, 4, 5];
        const arr2 = [];;
    </script>
</head>
<body>
    <div class="flex">
        <div></div>
        <div></div>
        <div></div>
    </div>
</body>

</html>